You can't make folders on the desktop that have "System Action" or "Device" references such
as con, nul and prn. Solution is to use another name or use 0 instead of o,O for C0n.
Here are others :
CON, PRN, AUX, CLOCK$, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9,
LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, LPT9